Extensible car radio antenna



Patented Dec. 20, 1949 UNITED STATES PATENT OFFICE EXTENSIBLE RADIOANTENNA Irving Bernstein and Murray Director,

Brooklyn, N. Y.

Application November 20, 1946, Serial N 0. 711,126

4 Claims.

This invention .relatesto extensible radio antennae and moreparticularly to such antennae designed for use upon moving vehicles suchas an automobile. It is an object of this invention to provide a radioantenna of the character described in which the metal parts are allprotected against corrosion, and may be made of a color designed toharmonize with the trimmings of the car, but which nevertheless willgive firm connection between the various extensible portions so thatnoise-making factors are eliminated.

It has heretofore been proposed to provide telescopic antennae havingmetal surfaces in which the friction required for holding the antennaextended is between those metal surfaces. Such antennae become hard toextend and contract as soon as the metal surfaces become corroded ordirty. Moreover, it frequently happens that the bright metallic colordoes not harmonize with the trimmings of the car.

It has also been proposed to provide a telescopic antenna havinginternal mechanism for making contacts between the extensible sections,but in such constructions, the internal contact device was not designedto serve as a means of steadying the telescopic parts relative to eachother.

The invention accordingly comprises a device possessing the features,properties and the relation of elements which will be exemplified in thearticle hereinafter described and the scope of the application of whichwill be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawings, in which:

Fig. 1 is a vertical section through an antenna embodying thisinvention. Fig. 2 is a section on the line 2-2 of Fig. 1, and Fig. 3 isa section on the line 3-3 of Fig. l.

The antenna of this construction embodies primarily three telescopicsections, I0, I I, and I2.

'The sections I and II are each composed of an inner tubular member I3,I 4, and an outer plastic sleeve I5, I6, while the upper section I2comprises an inner metallic rod I1, and an outer plastic sleeve I8.These three plastic sleeves are each firmly fixed upon the metallicmember which they Surround. There is appreciable clearance between theouter diameter of the plastic sleeve l8 and the inner diameter of thetubular member I4, and similarly there is an appreciable clearancebetween the outer diameter of the plastic sleeve I6, and the innerdiameter of the tubular member I 3. Firmly fixed upon the upper end ofthe sections I0 and II are two plastic knobs or balls, shown as balls I9and 20, which have openings 2| and 22 having a relatively closer fit 2about the mating plastic sleeves I6 and It, the diameter of this openingbeing materially smaller than the inner diameter of the members or tubesI3 and I4, so that the bearing engagement is between the balls and theplastic members rather than between the inner diameter of the tubularmembers of the plastic members.

As will be seen from the drawings, the rod IT has an extension I'I belowthe lower end of thev plastic member i8, and similarly the tube I4 hasan extension I l' below the lower end of the plastic sleeve I6. Each ofthe extensions IT and I4 is provided with two pairs of oppositelydisposed recesses adapted to receive balls 23 and maintain them inposition to bear against the inner surfaces of the tubular members I3and I4 respectively, and this engagement is a rather close fit so thatat the same time a good electrical contact is made and a firm support isgiven to the lower end of the sliding member.

By reason of the fact that the inner diameter of the tubes l3 and I4 isgreater than the openings in the balls l9 and 20, the extension of thedevice will be stopped as soon as the balls 23 come in contact with thelower edge of the openings 2| or '22. A felt washer 26 may be providedbelow the knobs to receive and cushion the blow as the balls comeagainst the stop. Similarly, the downward motion of each of the uppersections is limited by the contact between balls 20 and 27 with theballs I9 and 20 respective-1y.

As will be seen from the drawings, the lower end of the tube I3 extendsbelow the plastic sleeve I5 as shown at 25 to provide a means by whichthe antenna may be connected to the radio set of the car. This extensionis preferably closed by a plug 25a which will give inner support to thetube. At the upper end of the section I2 there may be also provided aball 2! serving to protect the upper end of the rod I1, and to givefinish to the top and at the same time complete the appearance of thedevice.

Since certain changes may be made in the above construction anddifferent embodiments of the invention could be made without departingfrom the scope thereof, it is intended that all matter contained in theabove description or shown in the accompanying drawings shall beinterpreted as illustrative and not in a limiting sense.

We claim:

1. A radio antenna comprising an outer section and an inner sectionslidable in said outer section, each of said sections comprising aplastic member, and a metallic member within. said plastic member havingan extension below the lower end thereof, a knob on the upper end ofsaid outer section having a sliding bearing for said inner section ofsmaller diameter than the inner diameter of said outer section withinwhich said inner section slides, there being a plurality of recessesupon said extension and balls within said recesses, frictionallyengaging the inner surface of said outer section to provide a tightfrictional bearing.

2. A radio antenna comprising an outer section and an inner sectionslidable therein, a knob upon the upper end of said outer section havinga slidable bearing of smaller diameter than the diameter of the sectionwithin which said inner sections slide, a plurality of recesses upon thelower end of said inner section arranged around the circumference, andballs within said recesses frictionally engaging the inner surface ofsaid outer section to provide a tight frictional bearing, and to serveas a stop when it engages the lower end of said first mentioned bearing.

3. A radio antenna comprising an outer section and an inner sectionslidable therein, a knob upon the upper end of said outer section havinga slidable bearing of smaller diameter than the diameter of the sectionwithin which said inner sections slide, a plurality of recesses upon thelower end of said inner section arranged in oppositely disposed pairs indifferent vertical planes, and balls within said recesses frictionallyengaging the inner surface of said outer section to provide a tightfrictional bearing, and to serve 4 as a stop when it engages the lowerend of said first mentioned bearing.

4. A radio antenna comprising an outer section and an inner section,said outer section having a bearing for the inner section adjacent itstop within which said inner section may slide, said inner section havinga plurality of ball sockets upon its lower end arranged in oppositelydisposed pairs, the ball in each of said sockets of a diameterfrictionally to engage the inner surface of said outer section.

IRVING BERNSTEIN. MURRAY DIRECTOR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

